<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css"
        integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
    <link rel="stylesheet" href="./style.css">
    <style>
        form {
            width: 50%;
            margin: auto;
        }
    </style>
</head>

<body>
    <header>
        <h1>学生管理系统</h1>
    </header>
    <form>
        <div class="form-group">
            <label for="exampleInputEmail1">账号</label>
            <input type="email" class="form-control" id="exampleInputEmail1" placeholder="Email">
        </div>
        <div class="form-group">
            <label for="exampleInputPassword1">密码</label>
            <input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
        </div>
        <div class="form-group">
            <label for="exampleInputPassword1">确认密码</label>
            <input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
        </div>

        <div class="checkbox">
            <label>
                <input type="checkbox"> Check me out
            </label>
        </div>
        <button type="button" class="btn btn-primary">提交</button>
    </form>

    <script>
        const users = [
            { username: 'zhangsan', password: '123' },
            { username: 'lisisi', password: '456' }
        ];

        let btn = document.getElementsByClassName('btn')[0];
        btn.onclick = function () {
            console.log('qqq');
        }

    </script>
</body>

</html>